Social Bookmarking site like Digg are becoming more popular these days. There are many new social bookmarking sites 
became popular in very few time. The reason for their popularity is that ever webmaster want their website can get loot of visitors and submitting their site to social bookmarking site can drive lot of visitors to their site.
If you are also looking to start your own social bookmarking site like Digg.com then you need website script to run your own site. I searched for social bookmarking script and I found some good scripts which can create a Digg type site. There are many Digg clone scripts but I have listed just 3 script which can really do good job.
As I have listed only 3 Scripts 2 of them are free and one is paid script.
Pligg – One of the most popular free social bookmarking scripts at this time. Pligg is an open source Content Management System (CMS) that you can download and use for free. Pligg CMS provides social networking software that encourages visitors to register on your website so that they can submit content and connect with other users. This software creates websites where stories are created and voted on by members, not website editors.
PHPDug - Another great free social bookmarking script. Create a site where users can rate and comment on stories or sites 
posted by your users just like digg.com.
Feature List
Easy to edit html template files
Spam fighting captcha security codes
Simple wizard installation
External dig buttons
Easy to edit language files
No need to setup a cronjob
Dig up/down comments
Powerful Admin panel for controlling your site
Automatic thumbnail retrieval for youtube and google videos
Automatically add stories from RSS feeds
MarkIt – MarkIt is a paid script costs $197 but worth to buy with its great features and support. There are many great features of this script which will help you to build professional site. MarkIt supports Open-ID and great features like Bookmark Management, Customized Profile, Network, Import/Export, Tags, Widgets, Subscription.
Thanks for the nice list..
Please keep it update.you can also see http://www.technowizpvtltd.com
OK cool to see- useful blogs are always helpful! See yas.
Hey Ravi Ahuja, special thanks.. because i could use this PHPDug application for my academic project. Thanks again..
thanks so much @ i love Pligg more than phpdug
I think i will try out Pligg
great post thanks for great information.
Pligg is the great software. I advice it.
Yes will give Pligg a try. Thanks guys!
i WANT DIGG CLONE SCRIPT
i am using pligg as social bookmarking script.
I found your website is very informative and enjoyable. Keep good work.
Yeah i’ve been using pligg for past couple of months and its the best,and thrs gonna be a new version getting ready to release iam eagerly waiting to see pligg 2.0
i’m using drigg for social bookmark site
i think not easy to download Pligg.
i already try several times to download but always Network Error or Files Not Founded